Back after a long lay off

[Cymrusaint]

Hi Guys, I haven't been on here for ages.
Trouble is my kids lost interest in the game. They'd rather play on the bloody Playstation. A lot easier see, they don't need to use their own imaginations, typical of kids today!
Anyway, I fancied playing again so I tried some single player rules and they worked well.
I've had an idea for a scenario, the problem I've got is that I need to create a whole new map board, none of the ones in the game will do. At present I'm trying to do it by cutting and pasting using Gimp2 and Microsoft Publisher it is very time consuming, and not much fun. Does anyone know of any software around that lets you create building maps. Preferably free!!!!